Chemistry - Ideal Gas Question with Solution | TestHub

Question Explanation: Find the new pressure of ${\mathrm{O}}_2$ when the container volume increases. C

oncept: Dalton's Law of Partial Pressures.

Solution:

Use Dalton's Law to find the initial pressure of ${\mathrm{O}}_2$. Then, apply Boyle's Law to find the new pressure after the volume changes, assuming temperature is constant.

${\mathrm{P}}_{\mathrm{T}}={\mathrm{P}}_{{\mathrm{O}}_2}+{\mathrm{H}}_2\mathrm{O}$

$720={\mathrm{P}}_{{\mathrm{O}}_2}+20\Rightarrow {\mathrm{P}}_{{\mathrm{O}}_2}=700$

$\mathrm{V}\to 4\mathrm{V}$

$\mathrm{P}\to \frac{1}{4}=\frac{700}{4}=\frac{350}{2}=175$

$\Rightarrow 175\mathrm{mm}$ of Hg

Final Answer: (A) 175 mm of Hg